The principles of Raja yoga (Rajha yoga) are compiled by sage Patanjali in the form of rules (also called a Ashtanga yoga, yoga with eight limbs).
The book contains a total of 195 rules in four chapters.
It will be difficult to comprehend clearly the teachings contained in the book without the help of an explanatory commentary and a teacher who has actually mastered the yogic practices.
The techniques of Raja yoga deal with the mind such as the control of mind and suppression of all its modifications. Raja yoga provides various methods in detail to how to restrain the thought waves (Maanas) and attaining the yoga consciousness.
A student of Raja yoga (called Raja yogi sadhaka) slowly ascends the yogic ladder by practicing the eight steps simultaneously. These steps are also called the eight limbs of the Raja yoga because they must be practiced simultaneously.
The eight limbs are:
Yamas ( Restraints)
Niyamas ( Religious Observances)
Asana ( Posture)
Pranayama ( Control of Breath)
Pratyahara ( Withdrawal of the Senses )
Dhyana ( Meditation)
Samadhi ( Yoga Conscious State)